Mump 1211 04 Ignition System Basics For Your Mustang

The typical round oil-filled ignition coil has three wire connections—the positive and negative primary wiring and the high-voltage secondary cable/plug wire. There are no moving parts to fail or wear, but the ignition coil's number one and two failure issues are heat and vibration. If at all possible, relocate the ignition coil off the engine to an inner fender panel away from engine exhaust heat and vibration.